Poor Idle Quality

ThunderBuzzard

Registered User
My '92 has an idle problem. It idles around 1000 RPM in Park, then after about 10 seconds the RPM drop to around 500 for about 5 seconds then they go back up to 1000. It keeps repeating this cycle.
I disconnected the battery hoping it would relearn it's idle but that didn't work. The car does it when it is hot or cold.
Does anyone have any idea what is wrong?
 
Tough one . Any Codes.

About the only thing you can do is check for codes. The eec is over compinsating . Do I dare say IAC, MAF ,fuel isues ,or vacume.
 
I pulled the trouble codes. The hard code is failure of the Canister Purge Solonoid, so I put a cap on the vacuum line. The engine running codes showed both o2 sensors are rich and the idle speed is low. So I changed out the Idle Speed Air Controller. That didn't fix it, so now the car is at Plaza Ford.
I'll let the pros fix it instead of blowing money changing out parts and hoping I hit the problem.
I'll keep you posted.
 
I checked my fuel pressure and it was swinging between 10 and 65 PSIG. When the pressure went low the engine stopped. I replaced the pump and now the engine runs smoothly. Now I need to replace that fuel pressure regulator...
 
Hey Thunderbuzzard

What kind of Fuel pressure regulator are you gonna use.
I have the same problems you have gas in the rail but no pressure. Anyone no if it could be a relay problem. Pump comes on for 5 sec when I turn the key on then shuts off like it has pressure but it don't. What tells the fuel pump to shut off?

I am really getting frustrated here. I have two of everything original OEM parts Rails, lines, pumps, regulators. Injectors. IT is all from 89 All this stuff was working before. Now I can't seem to get enough pressure in the rail. Just put on as new fuel filter still no pressure .


I hate to keep throwing money at the car but I am about to go ballistic and get eveything new. Went to napa they got a FPR for 47.00 from ford 65.00 advance auto 25.00 Has anyone tried the GPSorenson it is the cheapest does it work? Have seen some issues with aftermarket parts and was wondering.

Napa has the Fuel pump for 87.00 the guys at the counter told me that if it was coming on when I turn the key on then it is not the problem but you say yours was working and that it was the problem. What kind of Fuel pump did you replace with?

I was told after you replace the pump it should pressure the system. Did your pump? Did you have to do any thing else. Like use the diagnostic input to pressurize it. I was told you can force the pump to run to check it have not done this yet. Just can't figure out why pump turns on then shuts off right away before there is any pressure built up.
 
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Stocker the fuel pump shuts off because the comp tells it to. Once you start cranking the engine it will start back up, but the comp will not turn it back on until it gets a PIP signal from the crank sensor. The computer figures if its not getting a PIP signal that you are not trying to start the engine so it shuts the pump off.
Thats why you need you jump wire the pump to test it.
You dont want the engine starting up if your working on the fuel system, a gasoline bath is not fun.:)

The FPR you asked about works just fine, several guy's have used them and have not reported any problems.;)
 
Wow! It sounds like you have had it. MN12Perfofmance.com has a kit to replace your fuel pump. I used it and I am 100% satisfied. He has an excellent write up full of pictures on how to change it out. Check it out. I guess you could pinch off your fuel return hose to the fuel tank and see if your fuel pressure rises, if it does I would think the regulator is bad. Max fuel pump pressure for a Ford pump is around 65 PSIG.
I used the Walbro 190 lPH pump, email Rich with your setup and I'm sure he will lead you in the right direction.
To run your pump with the engine off you have to find the fuel pump relay on the left side of your trunk. My relay is green, and it has 4 wires going to it . Two thin and two thick wires(one of the thick wires is black and pink). Pull off the relay and use a piece of wire to jump the two thick wires together. You shold hear your fuel pump run. Then do your return line clamp and see what the fuel pressure does.
 
Wow that is EXCITING information THUNDERBUZZARD

I am ready to get it on . There is gonna be some action. Gonna finally get to the bottom of problem. When it is all done my fuel pressure will be correct. Then I can move to the next problem should there be any. It was all good before the pressure drop. Are the return lines mettle I hate to pinch them and bend them. I will have to check into that. Gonna figure it out even if I got to reach deep in my pockets. Anyone got anymore tricks?
 
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